All-country vs developed-only, whether Japan is included, emerging markets, cost, and who they suit.
Global equity funds hold shares across many countries in one product; all-country versions include developed, emerging, and Japanese markets, making a single fund a complete equity core for long horizons.
Global equity funds come in two broad flavours. An all-country fund (tracking an MSCI ACWI-type benchmark) holds developed markets, emerging markets, and Japan together — one product that approximates owning the whole listed world by market weight. A developed-only fund excludes emerging markets, and some developed benchmarks also exclude Japan, leaving you to add those sleeves separately.
For a beginner wanting simplicity, an all-country fund is the cleanest single-fund equity core. If you prefer to control the emerging-market or Japan weight yourself, a developed-only fund plus separate allocations is possible but more work.
Competitive Japanese global-equity index funds have very low trust fees, and several well-known low-cost options exist across fund families. Because the differences are small, also weigh tracking difference (how faithfully the fund delivers its index after costs) and assets under management (larger funds face less closure risk).
Most global funds are unhedged, so your yen return reflects both world equity performance and the yen exchange rate. This currency exposure is a deliberate diversification for many long-horizon investors, but understand it before buying. Availability is broker-specific; confirm the exact fund and NISA eligibility at your broker.
A single all-country fund can serve as your entire equity allocation, because it already holds the world by market weight. Whether that is your entire portfolio depends on whether you also need bonds or cash for stability — a 100% equity holding, even a globally diversified one, can still fall around 50% in a severe market. Combine it with safe assets according to how much loss you can tolerate.
Because one global fund is self-diversifying and low-maintenance, most beginners do not need a second equity fund on top of it. Adding an S&P 500 or Japan fund alongside mostly overlaps or tilts the weights, which is a deliberate choice rather than extra diversification.
Brokerage (NISA/iDeCo) · Rakuten Securities
A leading low-cost brokerage for NISA and index-fund investing, integrated with Rakuten points and Rakuten Bank.
Fees: Many domestic funds and trades are low- or no-commission — verify current fee schedule.
Brokerage (NISA/iDeCo) · SBI Securities
Japan’s largest online brokerage by accounts, with a very broad low-cost fund lineup and full NISA/iDeCo support.
Fees: Many trades and funds are low- or no-commission — verify current fee schedule.
Brokerage (NISA/iDeCo) · Monex
An established online brokerage often chosen for US-stock access and research tools, with NISA and iDeCo support.
Fees: Commissions vary by product; some funds/trades are low-cost — verify current schedule.
This is education, not a recommendation. Most beginners research low-cost, broadly diversified index funds — for example all-country (全世界株式) or S&P 500 trackers — rather than picking individual stocks, because low fees and diversification are within your control while returns are not. Understand that values fall as well as rise, match the risk to your time horizon, and never invest money you may need soon.